Fast food giant McDonald's announced a big move yesterday to begin posting calories on menu boards. It's also making smaller changes designed to help Americans make healthier choices; smaller changes you might not even notice.

But NPR's Allison Aubrey reports they can make a real difference.

ALLISON AUBREY, BYLINE: If you've eaten a burger or a chicken sandwich from McDonald's in the last year or so, have you noticed anything different in terms of saltiness? McDonald's director of nutrition, Cindy Goody, says they've reduced sodium 11 percent across national menu items. And with a nod towards addressing obesity, they've got a bunch of other changes in the works.

CINDY GOODY: So, by 2020, we have made a commitment to reduce not only added sugars but saturated fat and calories across our national menu.

AUBREY: But they plan to do it so gradually that customers probably won't notice. And according to McDonald's president, Jan Fields, none of this will get in the way of serving up the foods customers love.

JAN FIELDS: Since our start, McDonald's has always been known for its burgers and fries. And while I don't ever see that changing, we will continue to evolve our menu to satisfy our customers.

AUBREY: So do McDonald's customers see these healthy changes as something they want? We asked some.

BARBARA SMALLS: Not really.

(LAUGHTER)

SMALLS: If I was looking for something healthier or more nutritious, I probably would not be going to McDonald's.

AUBREY: Barbara Smalls says if McDonald's wants to encourage health, she's all for it. But in her view, the incremental steps sound too small to make a difference. After all, it's a burger and fries she's eating.

And 20-something Joseph Salahib(ph) says he's skeptical, too.

JOSEPH SALAHIB: I mean I guess they say they're trying but it's like more of like a marketing tool. Oh, we reduced our sodium by 15 percent.

AUBREY: Now, it may sound counterintuitive but public health experts say don't write off the small steps approach so fast. Obesity expert Barry Popkin, of the University of North Carolina, says initiatives like the ones McDonald's are pursuing could really pay off, especially if they really do quietly and incrementally shave sugar and calories from meals.

BARRY POPKIN: If McDonald's cut in that Big Mac 10 percent of its calories - and you didn't know it and that's all you bought - boy, it would matter over time.

AUBREY: And he says it works because customers get to keep ordering what they like.

POPKIN: This is what we call stealth changes. The consumer doesn't think they're buying anything different.

AUBREY: Consider this: American families get a lot of their calories from eating out. And for kids, this often means fast food meals. If the fast food industry cut sugar by just 20 percent, say, by reducing the size of sodas or desserts, this alone could amount to about 50 fewer calories every time a kid dined out.

Popkin says the typical overweight kid is only eating about 150 to 200 calories more than they should each day, so small reductions like this would soon add up. And the same is true for adults.

POPKIN: If you think of the average American adult consuming 2,000 or more calories a day, and you cut out 200 calories a day, that's huge.

AUBREY: But Popkin says to really move the dial on obesity you need the whole food sector, from restaurants to food retailers and manufacturers, working in tandem. And Larry Soler, the CEO of the Partnership for a Healthier America, says this has to be the way forward.

LARRY SOLER: No single initiative is going to solve this problem on its own, the problem of childhood obesity.

AUBREY: There are hints that coordinated efforts are emerging. Large restaurant groups, such as Darden, which owns the Olive Garden and Red Lobster chains, have made very similar commitments to cut calories and sugar. And on the retail end, big players such as Kroger's, Safeway and Wal-Mart all have initiatives, too.

Larry Soler is trying to nudge as many companies as possible to commit the changes.

SOLER: We're pushing them to do as much as much as they possibly can as fast as they can.

AUBREY: But it's a dance. With one step, companies are catering to consumers' old habits. And with the next, they are trying to lead them to a healthier place.